six.2.step one Diagnosing brand new Genus Revueltosaurus
This new holotypes from R. callenderi (NMMNH P-4957), “Revueltosaurus” hunti (NMMNH P-29357), in addition to recently charged varieties “Revueltosaurus” (= Pekinosaurus) olseni (YPM 7666; Heckert ainsi que al., 2012 ) per happened to be one isolated tooth that has been the basis for their particular analysis. Of late, Heckert mais aussi al. ( 2012 ) detected the genus Revueltosaurus (spanning R. callenderi, R. hunti, and you can R. olseni) utilizing the pursuing the blend of reputation claims: proportions (tooth crowns approximately eight to fifteen-mm significant); several small denticles (over seven for each and every carina) which can be counterbalance (sub-perpendicular) for the tooth margin; denticles proportionately short and sometimes worn to the tooth from the right occlusion; insufficient a genuine cingulum; premaxillary enamel crowns which can be approximately doubly significant just like the maxillary/dentary enamel crowns and you can weakly recurved; and you will maxillary/dentary enamel crowns phyllodont (leaf-shaped). grams., Ezcurra, 2016 ). Instance, the mixture of the measurements of tooth, the number of new denticles, additionally the direction of denticles overlap along with other distantly relevant taxa (e.g., Silesaurus opolensis, Dzik, 2003 ; Azendohsaurus madagaskarensis, Flynn mais aussi al., 2010 ). The smoothness “denticles proportionately short and sometimes worn on the tooth of the specific occlusion” lacks reliability regarding what is experienced “brief,” plus the don development is difficult to help you eliminate various other taxa and you may depends on a specific age tooth into the substitute for stage (i.elizabeth., young pearly whites would not be diagnosable because there wouldn’t be worn). In addition, its lack of apomorphic character states (elizabeth.grams., lack of cingulum) really should not be utilized in a diagnosis, because they’re symplesiomorphies. As well, the latest assignment of tooth reputation predicated on an individual enamel (age.grams., premaxillary enamel crowns is actually just as much as doubly high just like the maxillary/dentary tooth crowns and you can weakly recurved; maxillary/dentary tooth crowns leaf designed) cannot be determined regarding the fresh type of topic, and even with teeth regarding the exact same locality, merely craniodental question which have pearly whites provide the brand new association from enamel figure and you can tooth standing. Hence, the proposed enamel standing of the holotype pearly whites from K. hunti and you may P. olseni is believed based on an inferred intimate reference to R. callenderi, which is understood out-of craniodental cougar life desktop issue having white teeth (get a hold of more than). To summarize, brand new genus Revueltosaurus sensu lato can’t be adequately and you can sustainably diagnosed according to the type of information out-of Roentgen. callenderi, K. hunti, and P. olseni so we therefore limit the brand new genus to just one varieties, Roentgen. callenderi. Therefore, i propose that “R”. hunti keep up with the personal junior word Krzyzanowskisaurus hunti due to the fact erected from the Heckert ( 2005 ) and you can “R”. olseni retain the personal elder synonym Pekinosaurus olseni. I further caution the task of every existing isolated enamel taxa to Revueltosaurus.
We carry out realize that later, with more complete material, Roentgen. callenderi, Krzyzanowskisaurus hunti, and you may Pekinosaurus olseni get depict a beneficial monophyletic genus Revueltosaurus, however, a project of all three species to at least one genus is not already you’ll be able to since it tends to make a the priori presumption regarding the matchmaking (come across less than) that is parallel on brand-new argument the Revueltosaurus white teeth were assignable to help you Ornithischia to start with. This may features unwanted flowing outcomes into then macroevolutionary degree (elizabeth.g., biogeography and paleocology). Alternatively, it is reasonably quite possible these taxa may start out becoming distantly relevant.
six.2.2 What is Krzyzanowskisaurus hunti?
Heckert ( 2002 ) explained “Revueltosaurus” hunti, later allotted to this new genus Krzyzanowskisaurus (Heckert, 2005 ), centered on separated white teeth about Los Esteros Member of this new Santa Rosa Formation (Dockum Group) into the central The fresh new Mexico additionally the Bluish Mesa Person in new Chinle Formation when you look at the eastern Washington (style of area regarding Good. geoffreyi-find ), and contains also been approved throughout the down Chinle Creation when you look at the southeastern Utah ( , p. 16). Krzyzanowskisaurus hunti teeth is popular out-of R. callenderi teeth because of the visibility off a ridge (“cingulum”) at the base of your own enamel top, and this links to the carinae that will be have a tendency to denticulated (Heckert, 2002 , 2005 ; Irmis, Parker, mais aussi al., 2007 ; Rates 14a, b). In the first place, Krzyzanowskisaurus is titled considering the different morphology of the white teeth anywhere between the two variations in addition to disagreement the Krzyzanowskisaurus white teeth nonetheless was indeed assignable so you’re able to an enthusiastic ornithischian instead of good pseudosuchian (Heckert, 2005 ). Irmis, Parker, mais aussi al. ( 2007 ) disagreed to your assignment out of Krzyzanowskisaurus hunti for the Ornithischia created on the equivalent objections describing the difficulties of delegating separated white teeth so you can ornithischians just like the displayed prior to now and design you to definitely Heckert ( 2002 , 2005 ) recognized as a great “cingulum” was not homologous with the exact same formations inside ornithischian dinosaurs. Also, Irmis, Parker, et al. ( 2007 ) as well as indexed you to definitely an effective Revueltosaurus-such as for example squamosal, quadrate, and osteoderms had been as well as discovered at a comparable Washington area due to the fact Krzyzanowskisaurus hunti white teeth, exactly as had occurred within method of locality to have Roentgen. callenderi (Check ainsi que al., 2005 ).